Re: [PATCH V1] rtc: loongson: Add missing alarm notifications for ACPI RTC events

[Binbin Zhou]

On 2025/5/9 16:06, Liu Dalin wrote:
> 在 2025/5/9 15:12, Binbin Zhou 写道:
> > Hi:
> >
> > On 2025/5/9 09:40, Liu Dalin wrote:
> > > When an application sets and enables an alarm on Loongson RTC devices,
> > > the alarm notification fails to propagate to userspace because the
> > > ACPI event handler omits calling rtc_update_irq().
> > >
> > > As a result, processes waiting via select() or poll() on RTC device
> > > files fail to receive alarm notifications.
> > >
> > > Fixes: 1b733a9ebc3d ("rtc: Add rtc driver for the Loongson family 
> > > chips")
> > > Signed-off-by: Liu Dalin <liudalin@xxxxxxxxxxxxxxx>
> > Technically I don't think this is a compliant patch, firstly this 
> > patch should be V2 and also you should add "Changlog" for describing 
> > the differences from the previous patch.
> > Anyway, it's good to me.
>
> Ok! There is another problem, if regmap_write(priv->regmap,
> TOY_MATCH0_REG, 0) move to the end of loongson_rtc_handler as 
> 09471d8f5b39("rtc: loongson: clear TOY_MATCH0_REG in 
> loongson_rtc_isr()"), the interrupt also can be triggered multiple times.
>
> So the regmap_write(priv->regmap,TOY_MATCH0_REG, 0) is move behind of 
> rtc_update_irq by me, then the interrupt was triggered OK.
>
> Is there any problem ?

It is ok. That's where I added it when I suggested it before.

Thanks.
Binbin

> > Reviewed-by: Binbin Zhou <zhoubinbin@xxxxxxxxxxx>
> >
> > > ---
> > >   drivers/rtc/rtc-loongson.c | 8 ++++++++
> > >   1 file changed, 8 insertions(+)
> > >
> > > diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
> > > index 97e5625c064c..2ca7ffd5d7a9 100644
> > > --- a/drivers/rtc/rtc-loongson.c
> > > +++ b/drivers/rtc/rtc-loongson.c
> > > @@ -129,6 +129,14 @@ static u32 loongson_rtc_handler(void *id)
> > >   {
> > >       struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;
> > > +    rtc_update_irq(priv->rtcdev, 1, RTC_AF | RTC_IRQF);
> > > +
> > > +    /*
> > > +     * The TOY_MATCH0_REG should be cleared 0 here,
> > > +     * otherwise the interrupt cannot be cleared.
> > > +     */
> > > +    regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
> > > +
> > >       spin_lock(&priv->lock);
> > >       /* Disable RTC alarm wakeup and interrupt */
> > >       writel(readl(priv->pm_base + PM1_EN_REG) & ~RTC_EN,
> > Thanks.
> > Binbin